He insisted that he should be sent to work where he was needed most.这是什么从句?

这个句子主要有三点值得一提：
①that 引导的宾语从句,作insisted的宾语
②where引导的地点状语从句,是work的具体地点,注意不是work的宾语哦!wort at/in some place,这里的where相当于一个介词一个地点
③这里用到了should型虚拟,因为前面的谓语动词是insist,表示“坚决主张”.
要用虚拟的还有order,sugget,propose,command等动词,其中shoul可以省略,当句子这么出现时也要会看得出来：
He insisted that he be sent to work where he was needed most.